JP2002224131A - Inter-vertebral fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inter-vertebral fixing device which has a compact structure and in which a linear movement region and a revolution movement region can be widely set. SOLUTION: A linearly stretching and contracting part 21 having a movable member 24 moving linearly and an angle changeable part 22 having a revolution member 27 revolving in the all directions are provided and the movable member 24 of the linearly stretching and contracting part 21 is connected to the revolution member 27 of the angle changeable part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intervertebral fixation device which is attached between vertebrae after treating an affected part by a surgical operation when, for example, an intervertebral disc, a facet joint or a spine has a disorder. .

[0002]

2. Description of the Related Art Conventionally, in the case where an intervertebral disc, a facet joint, or a spine has an obstacle, the injured intervertebral disc or a part of the injured intervertebral joint or a deformed spine is removed by a surgical operation, and an artificial bone (such as apatite) is removed. After treatment such as embedding of an inorganic material), as shown in FIG. 5, the spinous processes 2a, 3a of the two vertebrae 2, 3 vertically adjacent to each other with the injured intervertebral disc 1 interposed therebetween, the pedicles 4 on both the left and right sides. 5. Screw the metal screws 8, 8 into the props 6, 7 from 5, and attach one metal plate 9 to the tips of the two screws 8, 8 corresponding to the upper and lower sides, and connect the vertically adjacent vertebrae 2 and 3. Fixed and dealt with pain and spinal instability.

[0003] However, the spine is originally movable, but if the spine is fixed with a metal plate so as not to move, if the body is forced to bend, bend, or twist, the spine will move above and below the fixed spine. The adjacent spine is also overloaded, damaging the disc just above and below the fixed spine, causing additional damage.

[0004] By moving the spine without applying excessive stress,
In addition, an artificial facet joint that brakes unreasonable movement of the body so as not to damage the facet joint or the intervertebral disc is disclosed in
No. 277070.

As shown in FIG. 6, the artificial facet joint 10 includes a cylinder part 11 having an open end, a piston part 12 movably disposed inside the cylinder part 11, and
It comprises a spring 13 disposed inside the piston portion and a lid 14 attached to the open end of the cylinder portion 11, and moves the piston portion 12 in a direction perpendicular to the moving direction in the cylinder portion 11 and the spine of a healthy person. It can be rotated to the angle of rotation.

[0006]

SUMMARY OF THE INVENTION
The piston moves linearly and rotationally with respect to the fixedly arranged cylinder.
The mechanism becomes large, and there is a limit to a compact structure. The present invention has been made in consideration of the above points, and has a compact structure, a linear motion area and a rotary motion area can be set to be large, and the spinning direction and torsional motion of the spine are ensured to ensure spine alignment. It is an object to provide an intervertebral fixation device that can be suppressed.

[0007]

According to the present invention, there is provided an intervertebral fixation apparatus comprising: a linear expansion / contraction part having a moving member that moves linearly; and an angle variable part having rotation means that rotates in all directions. The moving member is connected to the rotating means.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 to FIG.
Shows an intervertebral fixation device according to the present invention;
Is a linear expansion / contraction part 2 having a moving member that moves linearly.
1 and an angle varying unit 22 having a rotating means for rotating in all directions
It is composed of

The linear expansion / contraction part 21 has a cylinder part 23 formed of a cylindrical body and a piston part 24 formed of a rod inserted into the cylinder part 23 and moving inside the cylinder part 23 in the axial direction of the cylinder. . The inner surface 23a of the cylinder portion 23 may be provided with a lining layer made of a resin material or a ceramic material having high wear resistance. As the resin material, a polyurethane resin or a polyethylene resin is preferable. The piston portion 24 moves a predetermined length in the axial direction of the cylinder portion 23 while sliding on the inner surface 23a of the cylinder portion 23. Then, the straight elastic part 21
A mounting member 25 for screwing the piston portion 24 to the spine is fixed to the outer surface of the cylinder portion 23 opposite to the side where the piston portion 24 projects. The fixture 25 is a screw 25
The cylinder part 23 is fixed to the mounting part by a. The attachment 25 may be of a type fixed to the spine by hooks or wires.

In FIG. 1 to FIG. 3, the mounting member 25 fixes the cylinder portion 23 with the screw 25a on the axis of the screw portion fixed to the spine. Can be fixed by a screw 25a at a position offset from the axis of.

As shown in FIGS. 4 and 5, the mounting fixture 25 is screwed up and down into pairs of screw holes of the pushing bodies 6, 7 on the left and right sides. In this case, one fixture 25 fixes the cylinder portion 23 with the screw 25a on the axis of the screw portion fixed to the spine, and the other fixture 25 is offset from the axis of the screw portion fixed to the spine. The cylinder part 23 may be fixed at the position by the screw 25a.

In addition, both the attachments 25 may fix the cylinder portion 23 with the screw 25a at a position offset from the axis of the screw portion fixed to the spine. Can be set large.

The angle variable section 22 includes a spherical support surface 26a.
And a spherical support surface 26 of the body 26
a) and a spherical body 27 rotatably arranged in all directions. Body part 2 forming ball joint part
The spherical support surface 26a of No. 6 may be provided with a lining layer of a resin material or a ceramic material. Polyurethane resin and polyethylene resin are preferable as the resin material.
Further, a small-diameter shaft portion 28 is provided at an end of the main body 26 opposite to the side on which the ball joint portion is provided. An attachment 29 for screwing the variable angle part 22 to the spine is fixed to the small diameter shaft part 28 of the main body part 26. The attachment 29 may be of a type fixed by hooks or wires.

The intervertebral fixation device 20 includes a
The end portion of the piston portion 24 protruding from the cylinder portion 23 is connected to a sphere 27 forming a ball joint portion of the angle variable portion 22. The intervertebral fixation device 20 is provided with a sphere 27 integrally at an end of a piston portion 24 protruding from a cylinder portion 23 of a linear expansion / contraction portion 21, and the sphere 27 is formed into a spherical support surface forming a ball joint portion of an angle variable portion 22. 26a.

In the intervertebral fixation device 20, the piston portion 24 is movable in the cylinder portion 23, and the rotation of the spine of the healthy person is also performed by the angle variable portion 22 in the direction orthogonal to the moving direction in the cylinder portion. Since the body can be rotated by an angle, the two vertebrae vertically adjacent to each other can be moved within a restricted range when the body is bent back and forth or bent left and right.

Next, the operation will be described. Intervertebral fixation device 20
As a preparatory step, screw holes are drilled in the pedicles 6 and 7 from the pedicles 4 and 5 on both left and right sides of the spinous processes 2a and 3a of two spines 2 and 3 vertically adjacent to each other with the injured disc 1 interposed therebetween. (See FIG. 5).

Next, as shown in FIGS. 4 and 5, screw fittings 25 and 29 which form a pair up and down are screwed into the screw holes of the push bodies 6 and 7 on both the left and right sides. In this case, the cylinder part 23 of the linear expansion and contraction part 21 of the intervertebral fixation device 20 is fixed to the upper one of the upper and lower mounting tools 25 and 29 via the screw 25a. Fixture 29 located at
Then, the main body 26 of the variable angle portion 22 of the intervertebral fixation device 20 is fixed via the screw 29a.

Thus, the two intervertebral fixation devices 20
The spinous processes 2a, 3a of the spine 2, 3 are attached to predetermined positions on both left and right sides.

When the body is bent, the vertebrae 2 and 3 contract as shown by the angle A in FIG. 4, but at this time, the piston 24 of the linear expansion and contraction portion 21 of the intervertebral fixation device 20 moves along the inner surface of the cylinder 23 along the axis. Vertebrae 2 and 3
Can move without restriction to the intervertebral fixation device 20 and turn the body back.

When bending over the body, the spine 2 vertically adjacent
And the spine 3 moves as shown by angle B in FIG.
Since the piston portion 24 of the linear expansion and contraction portion 21 of the intervertebral fixation device 20 slides along the inner surface of the cylinder portion 23 so as to extend in the axial direction, the vertebrae 2 and 3 move without being restricted by the intervertebral fixation device 20, Can lean over the body.

When the body is bent left and right, the spine 2 and the spine 3
On the side where the space has shrunk, the intervertebral fixation device 20 shrinks,
On the side where the spine 2 and spine 3 expand, the intervertebral fixation device 20 extends. Therefore, the vertebrae 2, 3 move without being fixed to the intervertebral fixation devices 20, 20, and the body bends right and left.

When the body is forcibly bent left and right, in the intervertebral fixation device 20 on the contracted side, the end surface of the cylinder portion 23 hits the main body portion 26 of the angle variable portion 22 and the piston portion 24 The movement in the cylinder part 23 can also be restricted. In the intervertebral fixation device 20 on the expanded side, linear movement of the piston portion 24 in the cylinder portion 23 is restricted. To that end, further bending of the body can also be braked.

In the above-described embodiment, the turning member of the variable angle portion is a ball joint having a sphere 27, but the turning member of the variable angle portion is an elliptical ball or a universal joint type turning member. May be used.

[0024]

The intervertebral fixation device according to the present invention includes a linearly expanding / contracting portion having a moving member that moves linearly, and an angle changing portion having a rotating member that rotates in all directions. Because it is connected to the moving member, the structure is compact, the linear motion area and the rotary motion area can be set large, and it can follow the motion of the spine while maintaining the intervertebral alignment and create a healthy disc. Don't hurt.

[Brief description of the drawings]

FIG. 1 is a perspective view of an intervertebral fixation device according to the present invention.

FIG. 2 is a plan view of an intervertebral fixation device according to the present invention.

FIG. 3 is a side view of an intervertebral fixation device according to the present invention.

FIG. 4 shows a state in which the intervertebral fixation device according to the present invention is attached to the spine.

FIG. 5 is a view showing a conventional spinal fixation device.

FIG. 6 is a view showing a conventional intravertebral fixation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Intervertebral fixation device 21 Linear expansion / contraction part 22 Angle variable part 23 Cylinder part 24 Piston part 25 Fixture 26 Main body 27 Spherical body 29 Fixture

Claims (5)

[Claims] The present invention is characterized in that it comprises a linear expansion / contraction part having a moving member that moves linearly, and an angle variable part having a rotating means that rotates in all directions, wherein the moving member is connected to the rotating means. Intervertebral fixation device. 2. The intervertebral fixation device according to claim 1, wherein the moving member and the rotating means have an integral structure. 3. The intervertebral fixation device according to claim 1, wherein the linear expansion / contraction part has a cylinder part and a piston part movably mounted on the cylinder part. 4. The intervertebral fixation device according to claim 1, wherein the rotation means of the variable angle portion is a ball joint. 5. The intervertebral fixation according to claim 1, further comprising a mounting tool for mounting the linear elastic portion and the variable angle portion between adjacent vertebrae with the damaged intervertebral disc interposed therebetween. apparatus.